Here's a short (12 page) and pretty easy article from The Astrophysical Journal (2003), about end of life for massive stars. And why some would "directly" collapse (no big & bright supernova) into black holes.
Imagine seeing that up fairly close - a massive star just shrivel into a black hole and wink out.
pavel_lishin · 10d ago
I'd love to see a realistic render of this.
bell-cot · 11d ago
It's been a while since I crawled Wikipedia's rabbit hole on this - but I recall there being regions of the stellar "mass vs. metallicity" graph in which direct collapse to a black hole is the expected outcome.
Is there an astrophysicist in the house?
magicalhippo · 10d ago
Seems this is the case for both supermassive black hole formation[1][2], and stellar direct-collapse black holes due to failed supernova[3].
But yeah, just a layman so hopefully someone knowledgeable chimes in.
not an astro anything, but the easy question is how does the sun switch off it's light output so suddenly as to cause a perfect garavitational collapse
presumably it has to be a large metal rich star and exist without too much local gas or a companion star
one thing is clear at this point is that the variety of stelar and galactic variability is much larger than what was predicted even a few decades ago, though the idea of a star just neatly removing itself from this universe when it's done, is very strange indeed
madaxe_again · 11d ago
It doesn’t necessarily switch anything off or collapse - it’s possible for a star of the right mass and density to simply end up with a core that is held up only by degeneracy pressure, and the core slowly shrinks as it cools until it lies within its schwarzschild radius, and the rest of the star is either quietly consumed by this relatively slow process, or just escapes as though nothing much happened. Which from the outside looks like the star just turning off.
MoonGhost · 11d ago
It cannot just escape without a push as the gravity is still the same?
saltcured · 10d ago
I assume they meant until all the mass collapses across the threshold, the remaining shell of the star outside is still radiating energy and a "solar" wind, which is particles escaping. So some is escaping away while some is slipping under.
amelius · 11d ago
What is the timespan of such an event?
ben_w · 11d ago
Depends how you define the boundry of the event itself, both in space and in time.
Stellar cores are relatively small, and the infalling matter is essentially in freefall at high g, gets to a significant fraction of c in about 0.1 seconds.
The visible disk of a red supergiant — of the kind that can supernova or surprise us by failing — is on the order of multiple AU radius, so speed of light limits there are in the tens of minutes.
mikhailfranco · 9d ago
As many as 30 percent of such stars
may quietly collapse into black holes
no supernova required.
where 'such' refers to 25 solar mass stars.
Is that a significant contribution to 'dark matter'?
therealfiona · 10d ago
Here is an article about some JWST data of the star.
That's subjective. Objectively, all we can say is that it happened before 2017.
gerad · 10d ago
No it’s relative. ;)
pavel_lishin · 10d ago
Well, it certainly didn't happen tomorrow.
exe34 · 10d ago
in some reference frames, yes.
wizzwizz4 · 10d ago
No, not if we've observed it. There are predicted historical events which can be shunted into the future by running away bravely, but if you've seen them happen, you can only change how long ago.
exe34 · 10d ago
not for us, but in some other reference frame.
wizzwizz4 · 10d ago
If by "reference frame" you mean "observer who lives in the past", then yes: the past is sometimes the future of a more distant past.
exe34 · 9d ago
no, relativity allows for reference frames where the event hasn't happened yet, even though it has happened for you. there's no simultaneous "it has already happened" for all frames.
wizzwizz4 · 9d ago
There is if the event is in the past or future light cone. If A sends a signal to B, and B receives it, there is no reference frame where that signal went backwards in time. (Unless you count exotic ones, like "particle with imaginary rest mass is zooming along at thrice the speed of light", but you can't accelerate to such a reference frame so I don't.)
Scarblac · 10d ago
That was in 2017, it's 22000008 years ago now.
subscribed · 10d ago
Time doesn't pass uniformly :)
roman_soldier · 11d ago
Could be an advanced civilisation sucking all the stars energy into the back of their spaceship.
You basically let material stream into a black hole, it forms an acreation disk which gets very hot and dense even before the material actually falls into the black hole. The temperatture and pressure is high enough to trigger nucleosynthetic fusion reactions that generate heavy elements from lighter stuff, like the abundant hydrogen and helium. And a lot of "process heat" that can be used as energy source for other purposes. :)
adonovan · 10d ago
Perhaps a superadvanced civilization training an AI model on all remaining negative entropy in their solar system so they can more effectively create realistic propaganda for the upcoming election on their now rather chilly mars colony.
They could have used a dense Dyson sphere to “suck” the energy of the star, but if that was the case we would be able to detect its infrared radiation.
https://en.wikipedia.org/wiki/Dyson_sphere
Anyway, I prefer the giant star eating dragon alternative ;-)
chgs · 10d ago
And then where does it go?
keepamovin · 11d ago
Or something just moved in front of it. It did not rage against the dying of the light, the definition of out with a whimper.
WhitneyLand · 11d ago
Like people spent years of their life scientifically studying the problem and didn’t think of this before making the claim?
It was multi-wave analysis not just visible light, IR spread can differentiate this.
It’s been missing since 2015. Probability of something being large enough to cover the star and stay on a path completely obscuring it for 10 years is shall we say, not likely.
It didn’t rage against the dying of the light, it just switched off.
y42 · 11d ago
>As many as 30 percent of such stars, it seems, may quietly collapse into black holes — no supernova required.
gpvos · 10d ago
TFA says the astronomers checked for that. It's still a possibility, but pretty unlikely.
https://open.clemson.edu/cgi/viewcontent.cgi?article=1006&co...
Imagine seeing that up fairly close - a massive star just shrivel into a black hole and wink out.
Is there an astrophysicist in the house?
But yeah, just a layman so hopefully someone knowledgeable chimes in.
[1]: https://doi.org/10.1093/mnras/staa863
[2]: https://doi.org/10.3847/1538-4357/acda94
[3]: https://arxiv.org/abs/2503.23856
Stellar cores are relatively small, and the infalling matter is essentially in freefall at high g, gets to a significant fraction of c in about 0.1 seconds.
The visible disk of a red supergiant — of the kind that can supernova or surprise us by failing — is on the order of multiple AU radius, so speed of light limits there are in the tens of minutes.
Is that a significant contribution to 'dark matter'?
https://arxiv.org/abs/2309.16121
Orions Arm even has a story about how such process might look like: https://www.orionsarm.com/eg-article/46709da5de6be
You basically let material stream into a black hole, it forms an acreation disk which gets very hot and dense even before the material actually falls into the black hole. The temperatture and pressure is high enough to trigger nucleosynthetic fusion reactions that generate heavy elements from lighter stuff, like the abundant hydrogen and helium. And a lot of "process heat" that can be used as energy source for other purposes. :)
Joking aside, it could be a Kardashev Type II (or higher) civilization. https://en.wikipedia.org/wiki/Kardashev_scale
They could have used a dense Dyson sphere to “suck” the energy of the star, but if that was the case we would be able to detect its infrared radiation. https://en.wikipedia.org/wiki/Dyson_sphere
Anyway, I prefer the giant star eating dragon alternative ;-)
It was multi-wave analysis not just visible light, IR spread can differentiate this.
It’s been missing since 2015. Probability of something being large enough to cover the star and stay on a path completely obscuring it for 10 years is shall we say, not likely.
It didn’t rage against the dying of the light, it just switched off.